Light emitting device package and a lighting device

ABSTRACT

Provided are a light emitting device package and a lighting device. The light emitting device package includes a base, a light emitting device on the base, a plurality of electrode pads on the base, the plurality of electrode pads electrically connected to the light emitting device, a frame disposed on the base, wherein a size of the frame is smaller than a size of the base, a silver layer on a portion of the plurality of electrode pads, the silver layer directly contacted with the frame and an optical member covering the light emitting device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a 37 C.F.R. §1.53(b) continuation of U.S.patent application Ser. No. 12/792,589, filed Jun. 2, 2010 (now U.S.Pat. No. 8,044,423 issued on Oct. 25, 2011), which is a 37 C.F.R.§1.53(b) continuation of U.S. patent application Ser. No. 12/146,292,filed Jun. 25, 2008 (now U.S. Pat. No. 7,755,099 issued on Jul. 13,2010) and claims priority under 35 U.S.C. 119 Korean Patent ApplicationNo. 10-2007-0063771, filed on Jun. 27, 2007, each of which is herebyincorporated by reference in its entirety.

BACKGROUND

A light emitting diode (LED) is a semiconductor device that can berealized as various light emitting sources using compound semiconductormaterials such as GaAs, AlGaAs, GaN, InGaN, and AlGaInP.

The characteristics of the LED can be determined by a material, color,brightness, and the range of brightness intensity of a compoundsemiconductor. Also, the LED is packaged and is applied to variousfields such as a lighted-on display representing color, a characterdisplay, and an image display.

SUMMARY

Embodiments provide a light emitting device package that attaches asilicon wafer on a metal substrate and allows a light emitting device tobe mounted through an opening of the wafer, and a manufacturing methodthereof.

Embodiments provide a light emitting device package that can cover theouter periphery of a light emitting device with a reflective frameformed of silicon, and a manufacturing method thereof.

An embodiment provides a light emitting device package comprising: abase; a light emitting device on the base; a plurality of electrode padson the base, the plurality of electrode pads electrically connected tothe light emitting device; a frame disposed on the base, wherein a sizeof the frame is smaller than a size of the base; a silver layer on aportion of the plurality of electrode pads, the silver layer directlycontacted with the frame; and an optical member covering the lightemitting device.

An embodiment provides a lighting device comprising: a base; a lightemitting device on the base; a plurality of electrode pads on the base,the plurality of electrode pads electrically connected to the lightemitting device; a frame disposed on the base, wherein a size of theframe is smaller than a size of the base; a reflecting layer on aportion of the plurality of electrode pads, the silver layer directlycontacted with the frame; and an optical member covering the lightemitting device.

An embodiment provides a lighting device comprising: a base; a lightemitting device on the base; a plurality of electrode pads on the base,the plurality of electrode pads electrically connected to the lightemitting device; and a frame disposed on the base, wherein a size of anupper surface of the base is larger than a size of the frame, and aportion of at least one of the plurality of electrode pads formedoutside is emerged through a bottom of the frame and is parallel to thebase.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a light emitting device package according to anembodiment.

FIG. 2 is a side cross-sectional view of FIG. 1.

FIGS. 3 to 6 are views illustrating a method for manufacturing a lightemitting device package.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings.

FIG. 1 is a plan view of a light emitting device package according to anembodiment.

Referring to FIGS. 1 and 2, a light emitting device package 100comprises a silicon frame 101A, a base substrate 111, electrode pads 113and 115, and a light emitting diode 121.

The silicon frame 101A can comprise silicon and silicon carbide (SiC).When silicon is used, the frame can have a thinner thickness than thatof ceramic frame. Also, the silicon frame is not deformed depending ontemperature and time. That is, the silicon frame 101A has no shapedeformation or color change at high temperature compared to apolyphthalamide (PPA) resin.

Referring to FIG. 2, the silicon frame 101A is attached on the basesubstrate 111. Here, an adhesive 119 is used between the silicon frame101A and the base substrate 111. The adhesive 119 can comprise Ag pasteor a polymer resin material such as epoxy.

An opening is formed in the silicon frame 101A. The opening 103 is aportion in which the light emitting diode 121 is disposed. The surfaceof the opening can be formed in a circular shape or a polygonal shape.

A lateral side 105 is formed around the opening 103. The lateral side isformed to be inclined by 91-160° to the outer direction with respect tothe bottom to efficiently reflect incident light. Metal material havinghigh light reflectivity, such as Ag and Al can be formed on the lateralside 105.

The base substrate 111 can comprise a substrate formed of metal such asaluminum oxide, copper, and tungsten having high thermal conductivity.

An insulating layer 112 can be formed on the base substrate 111. Theinsulating layer 112 can be selected from a resin material, SiO₂, Si₃N₄,Al₂O₃, and TiO₂.

The plurality of electrode pads 113 and 115 are formed in a land shapeon the insulating layer 112. The plurality of electrode pads 113 and 115are electrically open inside the opening 103 and exposed to both sidesof the silicon frame 101A. In the case where a via hole (not shown) isformed in the base substrate 111, the plurality of electrode pads 113and 115 can be electrically connected to the lower portion of the basesubstrate 111 through the via hole.

The light emitting device 121 is attached on at least one of theelectrode pads 113 and 115 disposed in the opening 103 and electricallyconnected to the other electrode 115 using a wire 122. Here, in the casewhere the light emitting device 121 is a vertical semiconductor lightemitting device, it can be attached on the electrode pad 113 using aconductive adhesive. In the case where the light emitting device 121 isa lateral semiconductor light emitting device, it can be connected torespective electrode pads using a plurality of wires. Also, the lightemitting device 121 can be connected to the respective electrode pads113 and 115 using a flip method. There is no limitation in the chipstructure of the light emitting device 121, and a mounting method.

Also, at least one light emitting device 121 can be disposed in theopening 103. A color LED chip such as a blue LED chip, a green LED chip,a red LED chip, and a yellow LED chip, and an ultraviolet (UV) LED chipcan be selectively mounted as the light emitting device 103. Here, thelight emitting device 121 can be a compound semiconductor formed of amaterial such as GaAs, AlGaAs, GaN, InGaN, and AlGaInP.

A resin material 123 such as a transparent epoxy and silicon can be usedas a molding in the opening 103 where the light emitting device 121 isdisposed. Fluorescent material can be added to the resin material 123.For example, in the case where target light is white light for lightingor indication and the light emitting device 121 emits blue light, yellowfluorescent material can be added to the resin material 123. The yellowfluorescent material comprises but are not limited to YAG or yellowfluorescent material for silicate. A lens can be attached on the resinmaterial.

The light emitting device package 100 is a chip-on-board (COB) typepackage, and has excellent heatsink performance and excellent lightefficiency, so that it can be provided for use in a power package of 3 Wor more.

FIGS. 3 to 6 are views illustrating a method for manufacturing a lightemitting device package.

FIG. 3 is a plan view illustrating the silicon frame of FIG. 1.

Referring to FIG. 3, the silicon wafer 101 is the silicon frame of FIG.2, and can comprise a material such as silicon and silicon carbide(SiC). When silicon is used, the frame can have a thinner thickness (ex:minimum thickness of 150 μm) than that of ceramic frame. Also, thesilicon frame is not deformed depending on temperature and time.

The silicon wafer 101 is a nonconductor of electricity having electricalconductivity of 10¹⁰ Ωcm or more, and can be formed of a material havinghigh thermal conductivity of 140 W/mK or more.

The silicon wafer 101 comprises openings 103 and package boundary holes107. The openings 103 are separated with a constant interval andarranged in a matrix configuration. The opening 103 can have a circularor polygonal surface, which can be formed through a semiconductoretching process.

The lateral side 105 of the opening 103 is inclined by a predeterminedangle (ex: 90-160° C.) to the outer side with respect the bottom. Metalmaterial (ex: Ag and Al) having high light reflectivity can be depositedon the lateral side 105.

Also, the package boundary holes 107 can be formed with a constantinterval along the vertical direction and/or horizontal direction of thesilicon wafer 101, and can change depending on the dicing direction of aunit package. The package boundary hole 107 separates the openings 103to the left and right.

FIG. 4 is a plan view illustrating the base substrate of FIG. 1.

Referring to FIG. 4, the base substrate 111 can comprise a metalsubstrate formed of a material such as aluminum oxide, copper, andtungsten. The insulating layer 112 is formed on the base substrate 111.A pair of electrode pads 113 and 115 are formed on the insulating layer112.

The pair of electrode pads 113 and 115 are open, respectively, tocorrespond to the openings 103 (of FIG. 2), and are realized in a landpattern. The electrode pads 113 and 115 are formed with a constantinterval from the left to the right direction. One of the electrodes 113and 115 is formed in a larger size to allow a light emitting device tobe disposed thereon.

FIG. 5 is an exploded perspective view of a silicon wafer disposed on abase substrate, and FIG. 6 is a side cross-sectional view illustrating alight emitting device is mounted after a silicon wafer is attached on abase substrate.

Referring to FIG. 5, the silicon wafer 101 is disposed in the upperportion, and the base substrate 111 is disposed in the lower portion,and then they are aligned such that the openings 103 are disposed on theplurality of electrode pads 113 and 115. Also, the package boundary hole107 is disposed between the electrode pads 113 and 115 forming a pair.

Referring to FIGS. 5 and 6, an adhesive 119 is coated on the electrodepads 113 and 115 of the base substrate 111. The adhesive 119 cancomprise an Ag adhesive material or a polymer resin material such asepoxy. The lower surface of the silicon wafer 101 is attached on thebase substrate 111. At this point, the bottom of the opening 103 isdisposed such that the pair of electrode pads 113 and 115 areelectrically open.

The light emitting device 121 is attached on one of the electrode pads113 and 115 of the base substrate 111 disposed in the opening 103 usinga conductive adhesive, and connected to the other pad 115 using a wire122. Here, the light emitting device 121 comprises but is not limited toan LED chip manufactured using a compound semiconductor formed of GaAs,AlGaAs, GaN, InGaN, and AlGaInP. Also, the light emitting device 121 cancomprise one or more LED chips, for example, or one or morered/green/blue LED chips for a lighting purpose. The light emittingdevice 121 can be mounted on the electrode pads 113 and 115 using a wireor flip bonding, and is not limited thereto.

Also, at least one light emitting device 121 can be disposed in theopening 103 and is not limited thereto.

The light emitting device 121 is mounted on the base substrate 111 in aCOB type, so that it has excellent heatsink performance and excellentlight efficiency. Accordingly, the light emitting device 121 can beprovided for use in a power package of 3 W or more.

The resin material 123 is formed in the opening 103. At this point, theresin material 123 comprises a transparent silicon or epoxy. YAG oryellow fluorescent material for silicate can be added to the resinmaterial. For example, yellow fluorescent material can be added to theresin material 123 to excite blue light into yellow light and emit thesame.

After that, the silicon wafer 101 is diced in respective package unitsT1 using the package boundary holes 107, so that individual LED package100 can be obtained as illustrated in FIGS. 1 and 2.

Since an outer frame formed of silicon is used for the LED package, athinner package can be manufactured in comparison with using a ceramicmaterial. Also, since the outer frame formed of silicon is used,limitations by a shape and color can be complemented and thusreliability of the package improves.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is comprised in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A light emitting device package comprising: a base; a light emittingdevice on the base; a plurality of electrode pads on the base, theplurality of electrode pads electrically connected to the light emittingdevice; a frame disposed on the base, wherein a size of the frame issmaller than a size of the base; a silver layer on a portion of theplurality of electrode pads, the silver layer directly contacted withthe frame; and an optical member covering the light emitting device,wherein the silver layer is disposed between the frame and the portionof the plurality of electrode pads.
 2. The light emitting device packageaccording to claim 1, wherein the plurality of the electrode pads andthe base are coterminous at the lateral sides of the base.
 3. The lightemitting device package according to claim 1, wherein a portion of asurface of the plurality of electrode pads is exposed to an outer sideof the frame.
 4. The light emitting device package according to claim 1,wherein ends of the plurality of electrode pads are exposed to an outerside of the frame.
 5. The light emitting device package according toclaim 1, wherein a portion of a top surface of the plurality ofelectrode pads is exposed to an outer side of the frame.
 6. The lightemitting device package according to claim 1, wherein an entire portionof at least one of the plurality of electrode pads formed outside theframe is emerged through a bottom of the frame and is parallel to thebase.
 7. The light emitting device package according to claim 1, whereinthe base comprises a substrate and an insulating layer disposed betweenthe substrate and the plurality of electrode pads.
 8. The light emittingdevice package according to claim 1, wherein the base comprises a viahole.
 9. The light emitting device package according to claim 1, whereinthe frame comprises silicon or silicon carbide.
 10. The light emittingdevice package according to claim 1, wherein the frame comprises anopening and at least one side portion of the opening is coated with asecond silver layer, wherein a bottom of the second silver layer islower than a top surface of the light emitting device.
 11. The lightemitting device package according to claim 1, wherein the silver layeris inter-disposed on all boundary areas between the frame and theportion of the plurality of the electrode pads.
 12. The light emittingdevice package according to claim 10, wherein the light emitting deviceis disposed on one area of the plurality of electrode pads, and thesilver layer is also disposed on another area of the plurality ofelectrode pads where the light emitting device is disposed.
 13. Alighting device comprising: a base; a light emitting device on the base;a plurality of electrode pads on the base, the plurality of electrodepads electrically connected to the light emitting device; a framedisposed on the base, wherein a size of the frame is smaller than a sizeof the base; a silver layer on a portion of the plurality of electrodepads, the silver layer directly contacted with the frame; and an opticalmember covering the light emitting device, wherein the silver layer isdisposed between the frame and the portion of the plurality of electrodepads.
 14. The lighting device according to claim 13, wherein theplurality of the electrode pads and the base are coterminous at thelateral sides of the base.
 15. The light emitting device packageaccording to claim 13, wherein ends of the plurality of electrode padsare exposed to an outer side of the frame.
 16. The light emitting devicepackage according to claim 13, wherein a portion of a top surface of theplurality of electrode pads is exposed to an outer side of the frame.17. The light emitting device package according to claim 13, wherein anentire portion of at least one of the plurality of electrode pads formedoutside the frame is emerged through a bottom of the frame and isparallel to the base.
 18. A lighting device comprising: a base; a lightemitting device on the base; a plurality of electrode pads on the base,the plurality of electrode pads electrically connected to the lightemitting device; and a frame disposed on the base, wherein a size of anupper surface of the base is larger than a size of the frame, andwherein an entire portion of at least one of the plurality of electrodepads formed outside is emerged through a bottom of the frame and isparallel to the base.
 19. The lighting device according to claim 18,further comprising a silver layer on a portion of the plurality ofelectrode pads and the silver layer is directly contacted with theframe.
 20. The lighting device according to claim 18, wherein theplurality of the electrode pads and the base are coterminous at thelateral sides of the base.